Fan having hollow vanes for cooling the motor with external air

ABSTRACT

A fan assembly and associated methods are shown. Fan assemblies and methods include a fluid passage region defined between a fan motor and an outer housing. Example assemblies and methods include a number of hollow vanes located within the fluid passage region to permit an air flow between the fan motor and air external to the outer housing. In selected examples, fan motor cooling is facilitated using configurations described.

CLAIM OF PRIORITY

This application is a continuation of U.S. patent Ser. No. 15/172,471, filed Jun. 3, 2016, which application claims the benefit of priority to U.S. Provisional Application, Ser. No. 62/170,435, filed on Jun. 3, 2015, both of which are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

Embodiments described herein generally relate to fans. In selected examples, the present application relates more specifically to hollow vanes in a fan assembly and cooling configurations and methods.

BACKGROUND

Fans may be used for a number of end uses, including, but not limited to a general ventilation fan, a process fan, a central or jet fan for metro and tunnel ventilation, a mancooler, a drying jet fan, a wind tunnel fan, or similar applications. Many fan configurations utilize motors that are located within a ducted region. These motors generate significant heat while in operation, and their isolation within the ducted region can complicate heat transfer away from the motor. Examples of fan assemblies are described that address these, and other desires.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an isometric view of a fan assembly according to an example of the invention.

FIG. 2 shows an exploded view of a fan assembly according to an example of the invention.

FIG. 3 shows a side view of a fan assembly according to an example of the invention.

FIG. 4 shows a cross section view of a fan assembly according to an example of the invention.

FIG. 5A shows a cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 5B shows another cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 5C shows another cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 5D shows another cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 5E shows another cross section and top view of selected portion of a fan assembly according to an example of the invention,

FIG. 5F shows another cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 5G shows another cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 5H shows another cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 5I shows another cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 5J shows another cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 5K shows another cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 5L shows another cross section and top view of selected portion of a fan assembly according to an example of the invention,

FIG. 5M shows another cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 5N shows another cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 5O shows another cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 5P shows another cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 5Q shows another cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 5R shows another cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 5S shows another cross section and top view of selected portion of a fan assembly according to an example of the invention.

FIG. 6 shows a flow diagram of an example method of cooling a fan motor according to an example of the invention.

DESCRIPTION OF EMBODIMENTS

In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown, by way of illustration, specific embodiments in which the invention may be practiced. In the drawings, like numerals describe substantially similar components throughout the several views. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized and structural, or logical changes, etc. may be made without departing from the scope of the present invention.

FIG. 1 shows one example of a fan assembly 100. The fan assembly includes an inlet 114 coupled to a chamber 112. In impeller housing 116 is coupled to the chamber 112, and a flow housing 118 is coupled to the impeller housing 116. A number of vanes 120 are located within the flow housing 118. In the example of FIG. 1, a windband 110 is further coupled above the flow housing 118, although the invention is not so limited.

FIG. 2 shows an exploded view of the example fan assembly 100 from FIG. 1. The fan assembly 100 includes an inlet cone 134 coupled to a side of the chamber 112 and to the impeller housing 116. A first baffle 142 and a second baffle 144 are optionally included to selectively control air flow from the inlet 114 to the chamber 112, and from the chamber 112 to the inlet cone 134.

An impeller 132 is shown that is coupled to a motor 130. In the example shown, the motor 130 is housed within an interior space of the flow housing 118. FIG. 2 shows a motor housing 119 that is located within the flow housing 118, and defining a flow space 117 located between the flow housing 118 and the motor housing 119. FIG. 2 further shows the number of vanes 120 located within the flow space 117, and bridging between an inner diameter of the flow housing 118 to an outer diameter of the motor housing 119.

In one example, the vanes 120 are hollow vanes, as will be discussed in more detail below. In selected examples, hollow vanes 120 may permit air to flow between the inner diameter of the flow housing 118 the motor 130, located within the motor housing 119.

FIG. 3 shows a side view of the example fan assembly 100. The vanes 120 are shown spaced about the flow housing 118. A first vane side 124, a second vane side 126, and a vane tip 128 define a hollow space within the vane 120 that allows external air to enter the motor housing 119 and/or the flow space 117. In FIG. 3A, a portion of the motor 130 can be seen through one of the hollow vanes 120.

FIG. 4 illustrates yet another view of the example fan assembly 100 in cross section. The flow space 117 is shown between the motor housing 119 and the flow housing 118. A hollow vane 120 is shown passing through the flow space 117, and connecting the space outside the flow housing with the motor housing 119.

FIGS. 5A-5S show a number of examples of fan assembly configurations that utilize hollow vanes to cool a fan motor. Although any number of possible fan motors may be used in embodiments of the present invention, three types of motors are primary used to show cooling configurations in the following examples. 1) an Open Drip Proof Motor (ODP); 2) a Totally Enclosed Air Over Motor (TEAO); and 3) a Totally Enclosed Fan Cooled Motor (TEFC).

The configurations shown in FIGS. 5A-5S may not include all elements of a final fan assembly, such as the example fan assembly of FIGS. 1-4. The elements shown in FIGS. 5A-5S may be applied to any of a number of different fan assembly configurations, including, but not limited to the example of FIGS. 1-4.

FIG. 5A shows a side view of a fan assembly 500A. A top view 550A is further shown to better illustrate the example fan assembly 500A. A conduit is formed by an outer housing 502A, with a fan motor 504A located within the outer housing 502A. In one example, the fan motor 504A is a TEFC motor. A fluid passage 506A is defined between the fan motor 504A and the outer housing 502A. A number of vanes are shown within the fluid passage 506A. Vanes may be used to tune a flow of air moving through the fluid passage 506A, for example to straighten air flow. In one example, vanes 512A are used to support the fan motor 504A within the outer housing 502A.

An impeller 508A is shown coupled to a motor shaft 509A of the fan motor 504A. In the example shown, the impeller 508A drives a first amount of air through the fluid passage 506A, as indicated by arrows 520A. In the example shown, the first amount of air 520A is driven from an upstream end 501A towards a downstream end 503A of the fan assembly 500A. Although the term “air” is used for convenience in the present disclosure, other gasses or fluids may also be moved, driven, or otherwise utilized with embodiments of the present invention.

A number of hollow vanes 510A are shown, located within the fluid passage 506A. The hollow vanes 510A permit a second amount of air flow, indicated by arrows 522A, between the fan motor 504A and air external to the outer housing 502A. In the example of FIG. 5A, the second amount of air flow 522A moves in a direction from external to the outer housing, through the hollow vanes 510A, to the fan motor 504A, although the invention is not so limited. In other examples described below, the second amount of air flow 522A may flow from within the fluid passage 506A to the fan motor 504A, through the number of hollow vanes 510A, and to a region external to the outer housing. In other examples, the second amount of air flow 522A may flow in through one or more hollow vanes 510A, and out through one or more different hollow vanes 510A.

It may be desirable in a number of circumstances to cool the fan motor 504A with air from external to the outer housing 502A. For example, the first amount of air 520A may be at a temperature that is too hot to effectively cool the fan motor 504A. In such a circumstance, the second amount of air flow 522A may be cooler than the first amount of air 520A, and provide more effective motor cooling.

In one example, as illustrated in FIG. 5A, a second impeller 514A may be included to drive the second amount of air flow 522A between the fan motor 504A and air external to the outer housing. In one example the second impeller 514A may be driven by a common motor shaft by the same fan motor 504A that drives impeller 508A. Other examples may include a second impeller 514A that is driven separately by a different motor. In the example of FIG. 5A, the second impeller 514A is located on an opposite end of the fan motor 504A, although the invention is not so limited. In other examples, the second impeller 514A may be located on the same end of the fan motor 504A as the impeller 508A at a different axial spacing from the fan motor 504A.

In the example of FIG. 5A, the second amount of air flow 522A is mixed with the first amount of air 520A within the fluid passage 506A after cooling the fan motor 504A.

As stated above, a number of different configurations are shown in FIGS. 5A-5S. One common theme in the configurations shown includes hollow vanes that are used to cool a fan motor.

FIG. 5B shows a side view of a fan assembly 500B. A top view 550B is further shown to better illustrate the example fan assembly 500B. A conduit is formed by an outer housing 502B, with a fan motor 504B located within the outer housing 502B. In one example, the fan motor 504B is a TEAO motor. A fluid passage 506B is defined between the fan motor 504B and the outer housing 502B. A number of vanes are shown within the fluid passage 506B. Vanes may be used to tune a flow of air moving through the fluid passage 506B, for example to straighten air flow. In one example, vanes 512B are used to support the fan motor 504B within the outer housing 502B.

An impeller 508B is shown coupled to a motor shaft 509B of the fan motor 504B. In the example shown, the impeller 508B drives a first amount of air through the fluid passage 506B, as indicated by arrows 520B. In the example shown, the first amount of air 520B is driven from an upstream end 501B towards a downstream end 503B of the fan assembly 500B.

A number of hollow vanes 510B are shown, located within the fluid passage 506B. The hollow vanes 510B permit a second amount of air flow, indicated by arrows 522B, between the fan motor 504B and air external to the outer housing 502B. In the example of FIG. 5B, the second amount of air flow 522B moves in a direction from external to the outer housing, through the hollow vanes 510B, to the fan motor 504B, although the invention is not so limited.

In the example shown in FIG. 5B, the second amount of air flow 522B is moved through pressure differentials created by the first amount of air 520B and the impeller 508B. In the example of FIG. 5B, the second amount of air flow 522B is mixed with the first amount of air 520B within the fluid passage 506B after cooling the fan motor 504B.

FIG. 5C shows a side view of a fan assembly 500C. A top view 550C is further shown to better illustrate the example fan assembly 500C. A conduit is formed by an outer housing 502C, with a fan motor 504C located within the outer housing 502C. In one example, the fan motor 504C is a TEFC motor. A fluid passage 506C is defined between the fan motor 504C and the outer housing 502C. A number of vanes are shown within the fluid passage 506C. Vanes may be used to tune a flow of air moving through the fluid passage 506C, for example to straighten air flow. In one example, vanes 512C are used to support the fan motor 504C within the outer housing 502C.

An impeller 508C is shown coupled to a motor shaft 509C of the fan motor 504C. In the example shown, the impeller 508C drives a first amount of air through the fluid passage 506C, as indicated by arrows 520C. In the example shown, the first amount of air 520C is driven from an upstream end 501C towards a downstream end 503C of the fan assembly 500C.

A number of hollow vanes 510C are shown, located within the fluid passage 506C. The hollow vanes 510C permit a second amount of air flow, indicated by arrows 522C, between the fan motor 504C and air external to the outer housing 502C. In the example of FIG. 5C, the second amount of air flow 522C moves in a direction from external to the outer housing, through the hollow vanes 510C, to the fan motor 504C, although the invention is not so limited.

In one example, as illustrated in FIG. 5C, a second impeller 514C may be included to drive the second amount of air flow 522C between the fan motor 504C and air external to the outer housing. In one example the second impeller 514C may be driven by a common motor shaft by the same fan motor 504C that drives impeller 508C. Other examples may include a second impeller 514C that is driven separately by a different motor. In the example of FIG. 5C, the second impeller 514C is located on an opposite end of the fan motor 504C, although the invention is not so limited. In other examples, the second impeller 514C may be located on the same end of the fan motor 504C as the impeller 508C at a different axial spacing from the fan motor 504C.

In the example shown in FIG. 5C, the fan motor 504C is housed within an inner housing 530C that extends along a length of the fan motor 504C. This configuration may enhance cooling in some circumstances and increase aerodynamic efficiency within the fluid passage 506C. In the example of FIG. 5C, the second amount of air flow 522C is mixed with the first amount of air 520C within the fluid passage 506C after cooling the fan motor 504C.

FIG. 5D shows a side view of a fan assembly 500D. A top view 550D is further shown to better illustrate the example fan assembly 500D. A conduit is formed by an outer housing 502D, with a fan motor 504D located within the outer housing 502D. In one example, the fan motor 504D is a TEAO motor. A fluid passage 506D is defined between the fan motor 504D and the outer housing 502D. A number of vanes are shown within the fluid passage 506D. Vanes may be used to tune a flow of air moving through the fluid passage 506D, for example to straighten air flow. In one example, vanes 512D are used to support the fan motor 504D within the outer housing 502D.

An impeller 508D is shown coupled to a motor shaft 509D of the fan motor 504D. In the example shown, the impeller 508D drives a first amount of air through the fluid passage 506D, as indicated by arrows 520D. In the example shown, the first amount of air 520D is driven from an upstream end 501D towards a downstream end 503D of the fan assembly 500D.

A number of hollow vanes 510D are shown, located within the fluid passage 506D. The hollow vanes 510D permit a second amount of air flow, indicated by arrows 522D, between the fan motor 504D and air external to the outer housing 502D. In the example of FIG. 5D, the second amount of air flow 522D moves in a direction from external to the outer housing, through the hollow vanes 510D, to the fan motor 504D, although the invention is not so limited.

In the example shown in FIG. 5D, the second amount of air flow 522D is moved through pressure differentials created by the first amount of air 520D and the impeller 508D. In the example shown in FIG. 5D, the fan motor 504D is housed within an inner housing 530D that extends along a length of the fan motor 504D. This configuration may enhance cooling in some circumstances and increase aerodynamic efficiency within the fluid passage 506D. In the example of FIG. 5D, the second amount of air flow 522D is mixed with the first amount of air 520D within the fluid passage 506D after cooling the fan motor 504D.

FIG. 5E shows a side view of a fan assembly 500E. A top view 550E is further shown to better illustrate the example fan assembly 500E. A conduit is formed by an outer housing 502E, with a fan motor 504E located within the outer housing 502E. In one example, the fan motor 504E is an ODP motor. A fluid passage 506E is defined between the fan motor 504E and the outer housing 502E. A number of vanes are shown within the fluid passage 506E. Vanes may be used to tune a flow of air moving through the fluid passage 506E, for example to straighten air flow. In one example, vanes 512E are used to support the fan motor 504E within the outer housing 502E.

An impeller 508E is shown coupled to a motor shaft 509E of the fan motor 504E. In the example shown, the impeller 508E drives a first amount of air through the fluid passage 506E, as indicated by arrows 520E. In the example shown, the first amount of air 520E is driven from an upstream end 501E towards a downstream end 503E of the fan assembly 500E.

A number of hollow vanes 510E, are shown, located within the fluid passage 506E. The hollow vanes 510E permit a second amount of air flow, indicated by arrows 522E, between the fan motor 504E and air external to the outer housing 502E. In the example of FIG. 5E, the second amount of air flow 522E moves in a direction from external to the outer housing, through the hollow vanes 510E, to the fan motor 504E, although the invention is not so limited.

In the example shown in FIG. 5E, the second amount of air flow 522E is moved through pressure differentials created by the first amount of air 520E and the impeller 508E. In the example shown in FIG. 5E, the fan motor 504E is housed within an inner housing 530E that extends along a length of the fan motor 504E. In the example of FIG. 5E, the fan motor 504E further includes a number of internal passages 532E that allow a portion of the second amount of air flow 522E to flow through the fan motor 504E itself. Such a configuration may further enhance motor cooling. In the example of FIG. 5E, the second amount of air flow 522E is mixed with the first amount of air 520E within the fluid passage 506E after cooling the fan motor 504E.

FIG. 5F shows a side view of a fan assembly 500F. A top view 550F is further shown to better illustrate the example fan assembly 500F. A conduit is formed by an outer housing 502F, with a fan motor 504F located within the outer housing 502F. In one example, the fan motor 504F is a TEFC motor. A fluid passage 506F is defined between the fan motor 504F and the outer housing 502F. A number of vanes are shown within the fluid passage 506F. Vanes may be used to tune a flow of air moving through the fluid passage 506F, for example to straighten air flow.

An impeller 508F is shown coupled to a motor shaft 509F of the fan motor 504F. In the example shown, the impeller 508F drives a first amount of air through the fluid passage 506F, as indicated by arrows 520F. In the example shown, the first amount of air 520F is driven from an upstream end 501F towards a downstream end 503F of the fan assembly 500F.

A number of inlet hollow vanes 510F are shown, located within the fluid passage 506F. The inlet hollow vanes 510F permit a second amount of air flow, indicated by arrows 522F, between the fan motor 504F and air external to the outer housing 502F. A number of outlet hollow vanes 534F are further shown in FIG. 5F. The outlet hollow vanes 534F permit the second amount of air flow 522F to flow away from the fan motor 504F after heat exchange. As shown in the Figure, the second amount of air flow 522F flows back through the fluid passage 506E to a location external to the outer housing 502F. In the example shown, the inlet hollow vanes 510F are spaced apart axially from the outlet hollow vanes 524F, although the invention is not so limited. Other arrangements of inlet hollow vanes 510F and outlet hollow vanes 534F are discussed in more detail below. In one example, the second amount of air flow 522F is kept completely separate from the first amount of air 520F.

In one example, as illustrated in FIG. 5F, a second impeller 514F may be included to drive the second amount of air flow 522F between the fan motor 504F and air external to the outer housing. In one example the second impeller 514E may be driven by a common motor shaft by the same fan motor 504F that drives impeller 508F. Other examples may include a second impeller 514E that is driven separately by a different motor. In the example of FIG. 5F, the second impeller 514F is located on an opposite end of the fan motor 504F, although the invention is not so limited. In other examples, the second impeller 514F may be located on the same end of the fan motor 504E as the impeller 508F at a different axial spacing from the fan motor 504F.

FIG. 5G shows a side view of a fan assembly 500G. A top view 550G is further shown to better illustrate the example fan assembly 500G. A conduit is formed by an outer housing 502G, with a fan motor 504G located within the outer housing 502G. In one example, the fan motor 504G is a TEFC motor. A fluid passage 506G is defined between the fan motor 504G and the outer housing 502G. A number of vanes are shown within the fluid passage 506G. Vanes may be used to tune a flow of air moving through the fluid passage 506G, for example to straighten air flow.

An impeller 508G is shown coupled to a motor shaft 509G of the fan motor 504G. In the example shown, the impeller 508G drives a first amount of air through the fluid passage 506G, as indicated by arrows 520G. In the example shown, the first amount of air 520G is driven from an upstream end 503G towards a downstream end 501G of the fan assembly 500G.

A number of inlet hollow vanes 510G are shown, located within the fluid passage 506G. The inlet hollow vanes 510G permit a second amount of air flow, indicated by arrows 522G, between the fan motor 504G and air external to the outer housing 502G. A number of outlet hollow vanes 534G are further shown in FIG. 5G. The outlet hollow vanes 534G permit the second amount of air flow 522G to flow away from the fan motor 504G after heat exchange. In the example shown, the inlet hollow vanes 510G are spaced apart axially from the outlet hollow vanes 524G, although the invention is not so limited. Other arrangements of inlet hollow vanes 510G and outlet hollow vanes 534G are discussed in more detail below. As shown in the Figure, the second amount of air flow 522G flows back through the fluid passage 506G to a location external to the outer housing 502G. In one example, the second amount of air flow 522G is kept completely separate from the first amount of air 520G.

In one example, as illustrated in FIG. 5G, a second impeller 514G may be included to drive the second amount of air flow 522G between the fan motor 504G and air external to the outer housing. In one example the second impeller 514G may be driven by a common motor shaft by the same fan motor 504G that drives impeller 508G. Other examples may include a second impeller 514G that is driven separately by a different motor. In the example of FIG. 5G, the second impeller 514G is located on an opposite end of the fan motor 504G, although the invention is not so limited. In other examples, the second impeller 514G may be located on the same end of the fan motor 504G as the impeller 508G at a different axial spacing from the fan motor 504G.

FIG. 5H shows a side view of a fan assembly 500H. A top view 550H is further shown to better illustrate the example fan assembly 500H. A conduit is formed by an outer housing 502H, with a fan motor 504H located within the outer housing 502H. In one example, the fan motor 504H is a TEFC motor. A fluid passage 506H is defined between the fan motor 504H and the outer housing 502H. A number of vanes are shown within the fluid passage 506H. Vanes may be used to tune a flow of air moving through the fluid passage 506H, for example to straighten air flow.

An impeller 508H is shown coupled to a motor shaft 509H of the fan motor 504H. In the example shown, the impeller 508H drives a first amount of air through the fluid passage 506H, as indicated by arrows 520H. In the example shown, the first amount of air 520H is driven from an upstream end 503H towards a downstream end 501H of the fan assembly 500H.

A number of inlet hollow vanes 510H are shown, located within the fluid passage 506H. The inlet hollow vanes 510H permit a second amount of air flow, indicated by arrows 522H, between the fan motor 504H and air external to the outer housing 502H. A number of outlet hollow vanes 534H are further shown in FIG. 5H. The outlet hollow vanes 534H permit the second amount of air flow 522H to flow away from the fan motor 504H after heat exchange. In the example shown, the inlet hollow vanes 510H are on a same level axially as the outlet hollow vanes 524H but spaced apart radially, although the invention is not so limited. As shown in the Figure, the second amount of air flow 522H flows back through the fluid passage 506H to a location external to the outer housing 502H. In one example, the second amount of air flow 522H is kept completely separate from the first amount of air 520H.

In one example, as illustrated in FIG. 5H, a second impeller 514H may be included to drive the second amount of air flow 522H between the fan motor 504H and air external to the outer housing. In one example the second impeller 514H may be driven by a common motor shaft by the same fan motor 504H that drives impeller 508H. Other examples may include a second impeller 514H that is driven separately by a different motor. In the example of FIG. 5H, the second impeller 514H is located on an opposite end of the fan motor 504H, although the invention is not so limited. In other examples, the second impeller 514H may be located on the same end of the fan motor 504H as the impeller 508H at a different axial spacing from the fan motor 504H.

FIG. 5I shows a side view of a fan assembly 500I. A top view 550I is further shown to better illustrate the example fan assembly 500I. A conduit is formed by an outer housing 502I, with a fan motor 504I located within the outer housing 502I. In one example, the fan motor 504I is a TEFC motor. A fluid passage 506I is defined between the fan motor 504I and the outer housing 502I. A number of vanes are shown within the fluid passage 506I. Vanes may be used to tune a flow of air moving through the fluid passage 506I, for example to straighten air flow.

An impeller 508I is shown coupled to a motor shaft 509I of the fan motor 504I. In the example shown, the impeller 508I drives a first amount of air through the fluid passage 506I, as indicated by arrows 520I. In the example shown, the first amount of air 520I is driven from an upstream end 503I towards a downstream end 501I of the fan assembly 500I.

A number of hollow vanes 510I are shown, located within the fluid passage 506I. The hollow vanes 510I permit a second amount of air flow, indicated by arrows 522I, between the fan motor 504I and air external to the outer housing 502I. In the example of FIG. 5I, the second amount of air flow 522I moves in a direction from external to the outer housing, through the hollow vanes 510I, to the fan motor 504I, although the invention is not so limited.

In one example, as illustrated in FIG. 5I, a second impeller 514I may be included to drive the second amount of air flow 522I between the fan motor 504I and air external to the outer housing. In one example the second impeller 514I may be driven by a common motor shaft by the same fan motor 504I that drives impeller 508I. Other examples may include a second impeller 514I that is driven separately by a different motor. In the example of FIG. 5I, the second impeller 514I is located on an opposite end of the fan motor 504I, although the invention is not so limited. In other examples, the second impeller 514I may be located on the same end of the fan motor 504I as the impeller 508I at a different axial spacing from the fan motor 504I. In the example shown in FIG. 5I, the fan motor 504I is housed within an inner housing 530I that extends along a length of the fan motor 504I.

In the example of FIG. 5I, after cooling the motor 504I, the second amount of air flow 522I is exhausted into a hub 537I of the impeller 508I. An additional advantage of the routing of the second amount of air flow 522I in FIG. 5I is that a sub-assembly of the impeller 508I and the hub 537I, and bearings associated with the sub-assembly are more effectively cooled. After exhausting the second amount of air flow 522I into the low pressure interior of the hub 537I, the second amount of air flow 522I is directed through one or more openings 536I in the hub 537I, and is mixed with the first amount of air 520I within the fluid passage 506I. In the configuration of FIG. 5I, the second amount of air flow 522I is mixed with the first amount of air 520I at the upstream end 503I.

FIG. 5J shows a side view of a fan assembly 500J. A top view 550J is further shown to better illustrate the example fan assembly 500J. A conduit is formed by an outer housing 502J, with a fan motor 504J located within the outer housing 502J. In one example, the fan motor 504J is a TEAO motor. A fluid passage 506J is defined between the fan motor 504J and the outer housing 502J. A number of vanes are shown within the fluid passage 506J. Vanes may be used to tune a flow of air moving through the fluid passage 506J, for example to straighten air flow.

An impeller 508J is shown coupled to a motor shaft 509J of the fan motor 504J. In the example shown, the impeller 508J drives a first amount of air through the fluid passage 506J, as indicated by arrows 520J. In the example shown, the first amount of air 520J is driven from an upstream end 503J towards a downstream end 501J of the fan assembly 500J.

A number of hollow vanes 510J are shown, located within the fluid passage 506J. The hollow vanes 510J permit a second amount of air flow, indicated by arrows 522J, between the fan motor 504J and air external to the outer housing 502J. In the example of FIG. 5J, the second amount of air flow 522J moves in a direction from external to the outer housing, through the hollow vanes 510J to the fan motor 504J, although the invention is not so limited.

in the example shown in FIG. 5J the second amount of air flow 522J is moved through pressure differentials created by the first amount of air 520J and the impeller 508J. In the example shown in FIG. 5J, the fan motor 504J is housed within an inner housing 530J that extends along a length of the fan motor 504J.

In the example of FIG. 5J, after cooling the motor 504J, the second amount of air flow 522J is exhausted into a hub 537J of the impeller 508J. An additional advantage of the routing of the second amount of air flow 522J in FIG. 5J is that a sub-assembly of the impeller 508J and the hub 537J, and bearings associated with the sub-assembly are more effectively cooled. After exhausting the second amount of air flow 522J into the low pressure interior of the hub 537J, the second amount of air flow 522J is directed through one or more openings 536J in the hub 537J, and is mixed with the first amount of air 520J within the fluid passage 506J. In the configuration of FIG. 5J, the second amount of air flow 522J is mixed with the first amount of air 520J at the upstream end 503J.

FIG. 5K shows a side view of a fan assembly 500K. A top view 550K is further shown to better illustrate the example fan assembly 500K. A conduit is formed by an outer housing 502K, with a fan motor 504K located within the outer housing 502K. In one example, the fan motor 504K is an ODP motor. A fluid passage 506K is defined between the fan motor 504K and the outer housing 502K. A number of vanes are shown within the fluid passage 506K. Vanes may be used to tune a flow of air moving through the fluid passage 506K, for example to straighten air flow.

An impeller 508K is shown coupled to a motor shaft 509K of the fan motor 504K. In the example shown, the impeller 508K drives a first amount of air through the fluid passage 506K, as indicated by arrows 520K. In the example shown, the first amount of air 520K is driven from an upstream end 503K towards a downstream end 501K of the fan assembly 500K.

A number of hollow vanes 510K are shown, located within the fluid passage 506K. The hollow vanes 510K permit a second amount of air flow, indicated by arrows 522K, between the fan motor 504K and air external to the outer housing 502K. In the example of FIG. 5K, the second amount of air flow 522K moves in a direction from external to the outer housing, through the hollow vanes 510K, to the fan motor 504K, although the invention is not so limited.

In the example shown in FIG. 5K, the second amount of air flow 522K is moved through pressure differentials created b the first amount of air 520K and the impeller 508K. In the example shown in FIG. 5K, the fan motor 504K is housed within an inner housing 530K that extends along a length of the fan motor 504K.

In the example of FIG. 5K, after cooling the motor 504K, the second amount of air flow 522K is exhausted into a hub 537K of the impeller 508K. An additional advantage of the routing of the second amount of air flow 522K in FIG. 5K is that a sub-assembly of the impeller 508K and the hub 537K, and bearings associated with the sub-assembly are more effectively cooled. After exhausting the second amount of air flow 522K into the low pressure interior of the hub 537K, the second amount of air flow 522K is directed through one or more openings 536K in the hub 537K, and is mixed with the first amount of air 520K within the fluid passage 506K.In the configuration of FIG. 5K, the second amount of air flow 522K is mixed with the first amount of air 520K at the upstream end 503K.

FIG. 5L shows a side view of a fan assembly 500L. A top view 550L is further shown to better illustrate the example fan assembly 500L. A conduit is formed by an outer housing 502L, with a fan motor 504L located within the outer housing 502L. In one example, the fan motor 504L is an ODP motor. A fluid passage 506L is defined between the fan motor 504L, and the outer housing 502L. A number of vanes are shown within the fluid passage 506L. Vanes may be used to tune a flow of air moving through the fluid passage 506L, for example to straighten air flow.

An impeller 508L is shown coupled to a motor shaft 509L of the fan motor 504L. In the example shown, the impeller 508L drives a first amount of air through the fluid passage 506L, as indicated by arrows 520L. In the example shown, the first amount of air 520L is driven from an upstream end 503L towards a downstream end 501L of the fan assembly 500L.

A number of hollow vanes 510L are shown, located within the fluid passage 506L. The hollow vanes 510L permit a second amount of air flow, indicated by arrows 522L, between the fan motor 504L and air external to the outer housing 502L. In the example of FIG. 5L, the second amount of air flow 522L moves in a direction from external to the outer housing, through the hollow vanes 510L, to the fan motor 504L, although the invention is not so limited.

In the example shown in FIG. 5L, the second amount of air flow 522L is moved through pressure differentials created by the first amount of air 520L and the impeller 508L. In the example of FIG. 5L, the fan motor 504L includes a number of internal passages 532L that allow a portion of the second amount of air flow 522L to flow through the fan motor 504L itself. In the example of FIG. 5L, only an amount of the second amount of air flow 522L that passes through the internal passages 532L provides cooling to the fan motor 504L. This configuration provides a larger fluid passage 506L than configuration with inner housings as described above, and may improve fan performance.

in the example of FIG. 5L, after cooling the motor 504L the second amount of air flow 522L is exhausted into a hub 537L of the impeller 508L. An additional advantage of the routing of the second amount of air flow 522L in FIG. 5L is that a sub-assembly of the impeller 508L and the hub 537L, and bearings associated with the sub-assembly are more effectively cooled. After exhausting the second amount of air flow 522L into the low pressure interior of the hub 537L, the second amount of air flow 522L is directed through one or more openings 536L in the hub 537L, and is mixed with the first amount of air 520L within the fluid passage 506L. In the configuration of FIG. 5L, the second amount of air flow 522L is mixed with the first amount of air 520L at the upstream end 503L.

FIG. 5M shows a side view of a fan assembly 500M. A top view 550M is further shown to better illustrate the example fan assembly 500M. A conduit is formed by an outer housing 502M, with a fan motor 504M located within the outer housing 502M. In one example, the fan motor 504M is a TEFC motor. A fluid passage 506M is defined between the fan motor 504M and the outer housing 502M. A number of vanes are shown within the fluid passage 506M. Vanes may be used to tune a flow of air moving through the fluid passage 506M, for example to straighten air flow.

An impeller 508M is shown coupled to a motor shaft 509M of the fan motor 504M. In the example shown, the impeller 508M drives a first amount of air through the fluid passage 506M, as indicated by arrows 520M. In the example shown, the first amount of air 520M is driven from an upstream end 503M towards a downstream end 501M of the fan assembly 500M.

A number of hollow vanes 510M are shown, located within the fluid passage 506M. The hollow vanes 510M permit a second amount of air flow, indicated by arrows 522M, between the fan motor 504M and air external to the outer housing 502M. In the example of FIG. 5M, the second amount of air flow 522M moves in a direction from external to the outer housing, through the hollow vanes 510M, to the fan motor 504M, although the invention is not so limited.

In one example, as illustrated in FIG. 5M, a second impeller 514M may be included to drive the second amount of air flow 522M between the fan motor 504M and air external to the outer housing. In one example the second impeller 514M may be driven by a common motor shaft by the same fan motor 504M that drives impeller 508M. Other examples may include a second impeller 514M that is driven separately by a different motor. In the example of FIG. 5M, the second impeller 514M is located on an opposite end of the fan motor 504M, although the invention is not so limited. In other examples, the second impeller 514M may be located on the same end of the fan motor 504M as the impeller 508M at a different axial spacing from the fan motor 504M. Ire the example shown in FIG. 5M, the fan motor 504M is housed within an inner housing 530M that extends along a length of the fan motor 504J.

in the example of FIG. 5M, after cooling the motor 504M, the second amount of air flow 522M is exhausted into a hub 537M of the impeller 508M. An additional advantage of the routing of the second amount of air flow 522M in FIG. 5M is that a sub-assembly of the impeller 508M and the hub 537M, and bearings associated with the sub-assembly are more effectively cooled. After exhausting the second amount of air flow 522M into the low pressure interior of the hub 537M, the second amount of air flow 522M is directed through one or more openings 536M in the hub 537M, and is mixed with the first amount of air 520M within the fluid passage 506M. In the configuration of FIG. 5M, the second amount of air flow 522M is mixed with the first amount of air 520M at the upstream end 503M.

FIG. 5N shows a side view of a fan assembly 500N. A top view 550N is further shown to better illustrate the example fan assembly 500N. A conduit is formed by an outer housing 502N, with a fan motor 504N located within the outer housing 502N. In one example, the fan motor 504N is a TEAO motor. A fluid passage 506N is defined between the fan motor 504N and the outer housing 502N. A number of vanes are shown within the fluid passage 506N. Vanes may be used to tune a flow of air moving through the fluid passage 506N, for example to straighten air flow.

An impeller 508N is shown coupled to a motor shaft 509N of the fan motor 504N. In the example shown, the impeller 508N drives a first amount of air through the fluid passage 506N, as indicated by arrows 520N. In the example shown, the first amount of air 520N is driven from an upstream end 503N towards a downstream end 501N of the fan assembly 500N.

A number of hollow vanes 510N are shown, located within the fluid passage 506N. The hollow vanes 510N permit a second amount of air flow, indicated by arrows 522N, between the fan motor 504N and air external to the outer housing 502N. In the example of FIG. 5N, the second amount of air flow 522N moves in a direction from external to the outer housing, through the hollow vanes 510N, to the fan motor 504N, although the invention is not so limited. In the example shown in FIG. 5N, the fan motor 504N is housed within an inner housing 530N that extends along a length of the fan motor 504J on one side creating a swirling path for the second amount of air flow 522N around the fan motor 504J.

In the example of FIG. 5N, after cooling the motor 504N, the second amount of air flow 522N is exhausted into a hub 537N of the impeller 508N. An additional advantage of the routing of the second amount of air flow 522N in FIG. 5N is that a sub-assembly of the impeller 508N and the hub 537N, and bearings associated with the sub-assembly are more effectively cooled. After exhausting the second amount of air flow 522N into the low pressure interior of the hub 537N, the second amount of air flow 522N is directed through one or more openings 536N in the hub 537N, and is mixed with the first amount of air 520N within the fluid passage 506N. In the configuration of FIG. 5N, the second amount of air flow 522N is mixed with the first amount of air 520N at the upstream end 503N.

FIG. 5O shows a side view of a fan assembly 500O. A top view 550O is further shown to better illustrate the example fan assembly 500O. A conduit is formed by an outer housing 502O, with a fan motor 504O located within the outer housing 502O. In one example, the fan motor 504O is a TEAO motor. A fluid passage 506O is defined between the fan motor 504O and the outer housing 502O. A number of vanes are shown within the fluid passage 506O. Vanes may be used to tune a flow of air moving through the fluid passage 506O, for example to straighten air flow.

An impeller 508O is shown coupled to a motor shaft 509O of the fan motor 504O. In the example shown, the impeller 508O drives a first amount of air through the fluid passage 506O, as indicated by arrows 520O. In the example shown, the first amount of air 520O is driven from an upstream end 503O towards a downstream end 501O of the fan assembly 500O.

A number of hollow vanes 510O are shown, located within the fluid passage 506O. The hollow vanes 510O permit a second amount of air flow, indicated by arrows 522O, between the fan motor 504O and air external to the outer housing 502O. In the example of FIG. 5O, the second amount of air flow 522O moves in a direction from external to the outer housing, through the hollow vanes 510O, to the fan motor 504O, although the invention is not so limited. In the example shown in FIG. 5O, the fan motor 504O is housed within an inner housing 530O that extends along a length of the fan motor 504J on one side creating a swirling path for the second amount of air flow 522O around the fan motor 504J.

In the example of FIG. 5O, after cooling the motor 504O, the second amount of air flow 522O is exhausted into a hub 537O of the impeller 508O. An additional advantage of the routing of the second amount of air flow 522O in FIG. 5O is that a sub-assembly of the impeller 508O and the hub 537O, and bearings associated with the sub-assembly are more effectively cooled. After exhausting the second amount of air flow 522O into the low pressure interior of the hub 537O, the second amount of air flow 522O is directed through one or more openings 536O in the hub 537O, and is mixed with the first amount of air 520O within the fluid passage 506O. In the configuration of FIG. 5O, the second amount of air flow 522O is mixed with the first amount of air 5200 at the upstream end 503O.

FIG. 5P shows a side view of a fan assembly 500P. A top view 550P is further shown to better illustrate the example fan assembly 500P. A conduit is formed by an outer housing 502P, with a fan motor 504P located within the outer housing 502P. In one example, the fan motor 504P is an ODP motor. A fluid passage 506P is defined between the fan motor 504P and the outer housing 502P. A number of vanes are shown within the fluid passage 506P. Vanes may be used to tune a flow of air moving through the fluid passage 506P, for example to straighten air flow.

An impeller 508P is shown coupled to a motor shaft 509P of the fan motor 504P. In the example shown, the impeller 508P drives a first amount of air through the fluid passage 506P, as indicated by arrows 520P. In the example shown, the first amount of air 520P is driven from an upstream end 503P towards a downstream end 501P of the fan assembly 500P.

A number of hollow vanes 510P are shown, located within the fluid passage 506P. The hollow vanes 510P permit a second amount of air flow, indicated by arrows 522P, between the fan motor 504P and air external to the outer housing 502P. In the example of FIG. 5P, the second amount of air flow 522P moves in a direction from external to the outer housing, through the hollow vanes 510P, to the fan motor 504P, although the invention is not so limited.

in the example shown in FIG. 5P, the second amount of air flow 522P is moved through pressure differentials created by the first amount of air 520P and the impeller 508P. In the example shown in FIG. 5P, the fan motor 504P is housed within an inner housing 530P that extends at least partially around the fan motor 504P. In the example of FIG. 5P, the fan motor 504P further includes a number of internal passages 532P that allow a portion of the second amount of air flow 522P to flow through the fan motor 504P itself.

In the example of FIG. 5P, after cooling the motor 504P, the second amount of air flow 522P is exhausted into a hub 537P of the impeller 508P. An additional advantage of the routing of the second amount of air flow 522P in FIG. 5P is that a sub-assembly of the impeller 508P and the hub 537P, and hearings associated with the sub-assembly are more effectively cooled. After exhausting the second amount of air flow 522P into the low pressure interior of the hub 537P, the second amount of air flow 522P is directed through one or more openings 536P in the hub 537P, and is mixed with the first amount of air 520P within the fluid passage 506P. In the configuration of FIG. 5P, the second amount of air flow 522P is mixed with the first amount of air 520P at the upstream end 503P.

FIG. 5Q shows a side view of a fan assembly 500Q. A top view 550Q is further shown to better illustrate the example fan assembly 500Q. A conduit is formed by an outer housing 502Q, with a fan motor 504Q located within the outer housing 502Q. In one example, the fan motor 504Q is a TEFC motor. A fluid passage 506Q is defined between the fan motor 504Q and the outer housing 502Q. A number of vanes are shown within the fluid passage 506Q. Vanes may be used to tune a flow of air moving through the fluid passage 506Q, for example to straighten air flow.

An impeller 508Q is shown coupled to a motor shaft 509Q of the fan motor 504Q. In the example shown, the impeller 508Q drives a first amount of air through the fluid passage 506Q, as indicated by arrows 520Q. In the example shown, the first amount of air 520Q is driven from an upstream end 503Q towards a downstream end 501Q of the fan assembly 500Q.

A number of hollow vanes 510Q are shown, located within the fluid passage 506Q. The hollow vanes 510Q permit a second amount of air flow, indicated by arrows 522Q, between the fan motor 504Q and air external to the outer housing 502Q. In the example of FIG. 5Q, the second amount of air flow 522Q moves in a direction from inside the fluid passage 506Q, to the fan motor 504Q, then through the hollow vanes 510Q to the outer housing although the invention is not so limited.

In one example, as illustrated in FIG. 5Q, a second impeller 514Q may be included to drive the second amount of air flow 522Q between the fan motor 504Q and air external to the outer housing. In one example the second impeller 514Q may be driven by a common motor shaft by the same fan motor 504Q that drives impeller 508Q. Other examples may include a second impeller 514Q that is driven separately by a different motor. In the example of FIG. 5Q, the second impeller 514Q is located on an opposite end of the fan motor 504Q, although the invention is not so limited. In other examples, the second impeller 514Q may be located on the same end of the fan motor 504Q as the impeller 508Q at a different axial spacing from the fan motor 504Q.

In the example shown in FIG. 5Q, the fan motor 504Q is housed within an inner housing 530Q that extends around at least a portion of the fan motor 504J. In the example of FIG. 5Q, the second amount of air flow 522Q is directed from within the fluid passage 506Q, through one or more openings 538Q in a back fairing 539Q, and is expelled though hollow vanes 510Q after cooling the fan motor 504Q.

FIG. 5R shows a side view of a fan assembly 500R. A top view 550R is further shown to better illustrate the example fan assembly 500R. A conduit is formed by an outer housing 502R, with a fan motor 504R located within the outer housing 502R. In one example, the fan motor 504R is a TEAO motor. A fluid passage 506R is defined between the fan motor 504R and the outer housing 502R. A number of vanes are shown within the fluid passage 506R. Vanes may be used to tune a flow of air moving through the fluid passage 506R, for example to straighten air flow.

An impeller 508R is shown coupled to a motor shaft 509R of the fan motor 504R. In the example shown, the impeller 508R drives a first amount of air through the fluid passage 506R, as indicated by arrows 520R. In the example shown, the first amount of air 520R is driven from an upstream end 503R towards a downstream end 501R of the fan assembly 500R.

A number of hollow vanes 510R are shown, located within the fluid passage 506R. The hollow vanes 510R permit a second amount of air flow, indicated by arrows 522R, between the fan motor 504R and air external to the outer housing 502R. In the example of FIG. 5R, the second amount of air flow 522R moves in a direction from inside the fluid passage 506R, to the fan motor 504R, then through the hollow vanes 510R to the outer housing although the invention is not so limited.

In the example shown in FIG. 5R, the second amount of air flow 522R is moved through pressure differentials created by the first amount of air 520R and the impeller 508R. In the example shown in FIG. 5R, the fan motor 504R is housed within an inner housing 530R that extends around at least a portion of the fan motor 504J. In the example of FIG. 5R, the second amount of air flow 522R is directed from within the fluid passage 506R, through one or more openings 538R in a back fairing 539R, and is expelled though hollow vanes 510R after cooling the fan motor 504R.

FIG. 5S shows a side view of a fan assembly 500S. A top view 550S is further shown to better illustrate the example fan assembly 500S. A conduit is formed by an outer housing 502S, with a fan motor 504S located within the outer housing 502S. In one example, the fan motor 504S is an ODP motor. A fluid passage 506S is defined between the fan motor 504S and the outer housing 502S. A number of vanes are shown within the fluid passage 506S. Vanes may be used to tune a flow of air moving through the fluid passage 506S, for example to straighten air flow.

An impeller 508S is shown coupled to a motor shaft 509S of the fan motor 504S. In the example shown, the impeller 508S drives a first amount of air through the fluid passage 506S, as indicated by arrows 520S. In the example shown, the first amount of air 520S is driven from an upstream end 503S towards a downstream end 501S of the fan assembly 500S.

A number of hollow vanes 510S are shown, located within the fluid passage 506S. The hollow vanes 510S permit a second amount of air flow, indicated by arrows 522S, between the fan motor 504S and air external to the outer housing 502S. In the example of FIG. 5S, the second amount of air flow 522S moves in a direction from inside the fluid passage 506S, to the fan motor 504S, then through the hollow vanes 510S to the outer housing although the invention is not so limited.

In the example shown in FIG. 5S, the second amount of air flow 522S is moved through pressure differentials created by the first amount of air 520S and the impeller 508S. In the example shown in FIG. 5S, the fan motor 504S is housed within an inner housing 530S that extends around at least a portion of the fan motor 504J. In the example of FIG. 5S, the fan motor 504S further includes a number of internal passages 532S that allow a portion of the second amount of air flow 522S to flow through the fan motor 504S itself. In the example of FIG. 5S, the second amount of air flow 522S is directed from within the fluid passage 506S, through one or more openings 538S in a back fairing 539S, and is expelled though hollow vanes 510S after cooling the fan motor 504S.

FIG. 6 shows an example method of cooling a fan motor according to an embodiment of the invention. In operation 602, a first amount of air is moved through a fluid passage that is defined between an outer housing, and a fan motor located within the outer housing. In operation 604, a second amount of air flows through one or more hollow vanes through the fluid passage between a region external to the outer housing and the fan motor, wherein the second amount of air cools the fan motor. Example configurations shown above in FIGS. 5A-5S are capable of performing the example method of FIG. 6.

To better illustrate the method and apparatuses disclosed herein, a non-limiting list of embodiments is provided here:

Example 1 includes a fan assembly, including a conduit defined by an outer housing, a fan motor located within the outer housing, an impeller coupled to the fan motor to drive a first amount of air through a fluid passage region defined between the fan motor and the outer housing, and a number of hollow vanes located within the fluid passage region to permit a second amount of air flow between the fan motor and air external to the outer housing.

Example 2 includes the fan assembly of example 1 wherein the impeller is located at a downstream end of the conduit.

Example 3 includes the fan assembly of any one of examples 1-2, wherein the impeller is located at an upstream end of the conduit.

Example 4 includes the fan assembly of any one of examples 1-3, wherein the fan assembly is configured to move the second amount of air from external to the outer housing, through the number of hollow vanes, to the fan motor.

Example 5 includes the fan assembly of any one of examples 1-4, wherein the fan assembly is configured to further move the second amount of air from the fan motor and to mix with the first amount of air in the fluid passage.

Example 6 includes the fan assembly of any one of examples 1-5, wherein the fan assembly is configured to mix the second amount of air with the first amount of air at a downstream end of the fluid passage.

Example 7 includes the fan assembly of any one of examples 1-6, wherein the fan assembly is configured to mix the second amount of air with the first amount of air at an upstream end of the fluid passage.

Example 8 includes the fan assembly of any one of examples 1-7, wherein the fan assembly is configured to move the second amount of air from external to the outer housing, through inlet hollow vanes, to the fan motor, and back out through outlet hollow vanes.

Example 9 includes the fan assembly of any one of examples 1-8, wherein the fan assembly is configured to move the second amount of air from within the fluid passage to the fan motor, through the number of hollow vanes, and to a region external to the outer housing.

Example 10 includes the fan assembly of any one of examples 1-9, wherein the fan motor includes a totally enclosed fan cooled (TEFC) type motor with a second impeller to drive the second amount of air flow.

Example 11 includes the fan assembly of any one of examples 1-9, wherein the fan motor includes an open drip proof (ODP) type motor.

Example 12 includes the fan assembly of any one of examples 1-9, wherein the fan motor includes a totally enclosed air over (MAO) type motor.

Example 13 includes a fan assembly, including a conduit defined by an outer housing, a fan motor located within the outer housing, an impeller coupled to the fan motor to drive a first amount of air through a fluid passage region defined between the fan motor and the outer housing, a number of hollow vanes located within the fluid passage region to permit a second amount of air flow to move from external to the outer housing to the fan motor, and an exhaust passage for the second amount of air flow to move from the fan motor to a hollow portion within a hub of the impeller.

Example 14 includes the fan assembly of example 13, wherein the hub further includes exhaust openings to exhaust the second amount of air flow from within the hub and into the first amount of air.

Example 15 includes a fan assembly, including a conduit defined by an outer housing, a fan motor located within the outer housing, an impeller coupled to the fan motor to drive a first amount of air through a fluid passage region defined between the fan motor and the outer housing, a first set of inlet hollow vanes located within the fluid passage region to permit a second amount of air flow from external to the outer housing into the fan motor, and a second set of outlet hollow vanes located within the fluid passage region to permit the second amount of air flow from the fan motor back through the fluid passage, separated from the first amount of air.

Example 16 includes the fan assembly of example 15, wherein inlet hollow vanes are spaced axially apart from outlet hollow vanes.

Example 17 includes the fan assembly of any one of examples 15-16, wherein inlet hollow vanes are located on one side of the fan assembly, and outlet hollow vanes are located on a different side of the fan assembly.

Example 18 includes the fan assembly of any one of examples 15-16, further including a second impeller to drive the second amount of air.

Example 19 includes a method of cooling a fan motor including, moving a first amount of air through a fluid passage that is defined between an outer housing, and a fan motor located within the outer housing, and flowing a second amount of air through one or more hollow vanes through the fluid passage between a region external to the outer housing and the fan motor, wherein the second amount of air cools the fan motor.

Example 20 includes the method of example 19, wherein flowing the second amount of air includes actively driving a second amount of air using an impeller.

Example 21 includes the method of any one of examples 18-19, wherein flowing the second amount of air includes flowing the second amount of air back through one or more hollow vanes to the region external to the outer housing after cooling the fan motor.

Example 22 includes the method of any one of examples 18-20, wherein flowing the second amount of air includes flowing the second amount of air into the fluid passage and mixing the second amount of air with the first amount of air after cooling the fan motor.

The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as “examples.” Such examples can include elements in addition to those shown or described. However, the present inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the present inventors also contemplate examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.

In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” in this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. 

1. A fan assembly, comprising: a conduit defined by an outer housing; a fan motor located within the outer housing; a first impeller coupled to the fan motor to drive a first amount of air through a fluid passage region defined between the fan motor and the outer housing; a first set of inlet hollow vanes located within the fluid passage region to permit a second amount of air flow from external to the outer housing into the fan motor; and a second set of outlet hollow vanes located within the fluid passage region to permit the second amount of air flow from the fan motor back through the fluid passage, separated from the first amount of air.
 2. The fan assembly of claim 1, wherein inlet hollow vanes are spaced axially apart from outlet hollow vanes.
 3. The fan assembly of claim 1, wherein inlet hollow vanes are located on one side of the fan assembly, and outlet hollow vanes are located on a different side of the fan assembly.
 4. The fan assembly of claim 1, wherein the fan motor includes a totally enclosed fan cooled (TEFC) type motor with a second impeller to drive the second amount of air flow.
 5. The fan assembly of claim 1, wherein the fan motor includes an open drip proof (ODP) type motor.
 6. The fan assembly of claim 1, wherein the fan motor includes a totally enclosed air over (TEAO) type motor.
 7. The fan assembly of claim 1, wherein the impeller is orated at a downstream end of the conduit.
 8. The fan assembly of claim 1, wherein the impeller is located at an upstream end of the conduit.
 9. A fan assembly, comprising: a conduit defined by an outer housing; a fan motor located within the outer housing; a first impeller coupled to the fan motor to drive a first amount of air through a fluid passage region defined between the fan motor and the outer housing; a first set of inlet hollow vanes located within the fluid passage region to permit a second amount of air flow from external to the outer housing into the fan motor; a second set of outlet hollow vanes located within the fluid passage region to permit the second amount of air flow from the fan motor back through the fluid passage, separated from the first amount of air; and a second impeller to drive the second amount of air through the hollow vanes.
 10. The fan assembly of claim 9, wherein the first set of inlet hollow vanes includes two or more inlet hollow vanes.
 11. The fan assembly of claim 9, wherein the second set of outlet hollow vanes includes two or more outlet hollow vanes.
 12. The fan assembly of claim 9, wherein inlet hollow vanes are spaced axially apart from outlet hollow vanes.
 13. The fan assembly of claim 9, wherein inlet hollow vanes and outlet hollow vanes are spaced radially apart around the conduit at different radial locations.
 14. The fan assembly of claim 9, wherein the impeller is located at a downstream end of the conduit.
 15. The fan assembly of claim 9, wherein the impeller is located at an upstream end of the conduit.
 16. The fan assembly of claim 9, wherein the fan motor includes a totally enclosed fan cooled (TEFC) type motor with a second impeller to drive the second amount of air flow.
 17. The fan assembly of claim 9, wherein the fan motor includes an open drip proof (ODP) type motor.
 18. The fan assembly of claim 9, wherein the fan motor includes a totally enclosed air over (MAO) type motor. 